Birth characteristics and childhood carcinomas.

BACKGROUND: Carcinomas in children are rare and have not been well studied. METHODS: We conducted a population-based case-control study and examined associations between birth characteristics and childhood carcinomas diagnosed from 28 days to 14 years during 1980-2004 using pooled data from five states (NY, WA, MN, TX, and CA) that linked their birth and cancer registries. The pooled data set contained 57,966 controls and 475 carcinoma cases, including 159 thyroid and 126 malignant melanoma cases. We used unconditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: White compared with 'other' race was positively associated with melanoma (OR=3.22, 95% CI 1.33-8.33). Older maternal age increased the risk for melanoma (OR(per 5-year age increase)=1.20, 95% CI 1.00-1.44), whereas paternal age increased the risk for any carcinoma (OR=1.10(per 5-year age increase), 95% CI 1.01-1.20) and thyroid carcinoma (OR(per 5-year age increase)=1.16, 95% CI 1.01-1.33). Gestational age < 37 vs 37-42 weeks increased the risk for thyroid carcinoma (OR=1.87, 95% CI 1.07-3.27). Plurality, birth weight, and birth order were not significantly associated with childhood carcinomas. CONCLUSION: This exploratory study indicates that some birth characteristics including older parental age and low gestational age may be related to childhood carcinoma aetiology.

Parental educational attainment as an indicator of socioeconomic status and risk of childhood cancers.

BACKGROUND: Little has been reported on socioeconomic (SES) patterns of risk for most forms of childhood cancer. METHODS: Population-based case-control data from epidemiological studies of childhood cancer conducted in five US states were pooled and associations of maternal, paternal and household educational attainment with childhood cancers were analysed. Odds ratios (ORs) and 95% confidence intervals were estimated using logistic regression, controlling for confounders. RESULTS: Although there was no association with parental education for the majority of cancers evaluated, there was an indication of a positive association with lower education for Hodgkin's and Burkitt's lymphoma and Wilm's tumour, with the ORs ranging from 1.5 to >3.0 times that of more educated parents. A possible protective effect was seen for lower parental education and astrocytoma and hepatoblastoma, with ORs reduced by 30 to 40%. CONCLUSIONS: These study results should be viewed as exploratory because of the broad nature of the SES assessment, but they give some indication that childhood cancer studies might benefit from a more thorough assessment of SES.

Birth characteristics and the risk of childhood rhabdomyosarcoma based on histological subtype.

BACKGROUND: Little is known about risk factors for childhood rhabdomyosarcoma (RMS) and the histology-specific details are rare. METHODS: Case-control studies formed by linking cancer and birth registries of California, Minnesota, New York, Texas and Washington, which included 583 RMS cases (363 embryonal and 85 alveolar RMS) and 57 966 randomly selected control subjects, were analysed using logistic regression. The associations of RMS (overall, and based on embryonal or alveolar histology) with birth weight across five 500 g categories (from 2000 to 4500 g) were examined using normal birth weight (2500-3999 g) as a reference. Large (>90th percentile) and small (<10th percentile) size for gestational age were calculated based on birth weight distributions in controls and were similarly examined. RESULTS: High birth weight increased the risk of embryonal RMS and RMS overall. Each 500 g increase in birth weight increased the risk of embryonal RMS (odds ratio (OR)=1.27, 95% confidence interval (CI)=1.14-1.42) and RMS overall (OR=1.18, 95% CI=1.09-1.29). Large size for gestational age also significantly increased the risk of embryonal RMS (OR=1.42, 95% CI=1.03-1.96). CONCLUSIONS: These data suggest a positive association between accelerated in utero growth and embryonal RMS, but not alveolar RMS. These results warrant cautious interpretation owing to the small number of alveolar RMS cases.

Urban-rural residence and the occurrence of neural tube defects in Texas, 1999-2003.

Neural tube birth defects (NTDs) affect more than 4000 pregnancies in the US annually. The etiology of NTDs is believed to be multifactorial, but much remains unknown. We examined the pattern and magnitude of urban-rural variation in anencephaly, spina bifida without anencephaly, and encephalocele in Texas in relation with urban-rural residence for the period 1999-2003. There was no evidence that urban-rural residence was associated with changes in the rate of anencephaly or spina bifida without anencephaly in unadjusted or adjusted analyses. In contrast, rates of encephalocele were statistically significantly higher in areas classified as suburban or more rural compared to urban areas using four different urban-rural residence indicators.

Evaluation of the Texas 0.08 BAC law.

AIMS: The purpose of the present study was to assess the effects on alcohol-involved traffic crashes and fatalities of the 0.08 blood alcohol concentration (BAC) per se law introduced in the state of Texas in 1999. METHOD: Data pertaining to alcohol-involved traffic crashes and fatalities were extracted from two datasets: the Fatality Analysis Reporting System (FARS) compiled by the National Highway Traffic Safety Administration (for the period January 1995-September 2002), and the Texas Department of Public Safety (DPS) reports of Alcohol Related Motor Vehicle Traffic Accidents and Casualties (for the period January 1995-December 2000). The data were analysed using time-series methods (ARIMA routines). The effects of the law on all drivers were assessed, along with the effects among gender, racial, and age subgroups and crash location (urban vs rural). RESULTS: Separate time-series analyses were conducted with all alcohol-involved and fatal alcohol-involved crashes from the DPS dataset and fatal alcohol-involved crashes from the FARS dataset as the outcome variables. None of the effects for either the total sample or any of the subgroups analysed was statistically significant (this was true of both the FARS and DPS datasets). CONCLUSIONS: While there is a growing body of evidence that indicates that 0.08 BAC laws can be effective in reducing alcohol-involved traffic accidents and fatalities, the present study shows that this was not the case in Texas. Future research should move beyond the simple question of whether or not 0.08 BAC laws 'work' and instead explore in more detail the conditions, such as publicity and enforcement, under which the law does or does not contribute to a decline in alcohol-involved accidents and fatalities.

Subsite-specific incidence rate and stage of disease in colorectal cancer by race, gender, and age group in the United States, 1992-1997.

BACKGROUND: Subsite specific incidence rates of colorectal cancer vary considerably by age, gender, and race. This variation may be related not only to distinctions in exposure to genetic and environment factors but also to current strategies of early detection screening. Patterns of stage of disease in anatomic subsite may reflect the effect of screening. This study used the largest aggregation of cancer incidence data in the U.S. to examine subsite specific incidence rates of colorectal cancer and the relation of stage of disease to anatomic subsites by race, gender, and age group. METHODS: Data on the incidence of invasive colorectal cancer were obtained from 28 population-based central cancer registries. Age-specific and age-adjusted rates and stage distributions were analyzed by subsite, race, and gender. RESULTS: The impact of screening can be observed in the percentage of localized disease, which increased from 31.9% among cancers in the proximal colon to 37.0% in the descending colon to 41.5% in the distal colorectum. Within the same subsite, blacks were less likely than whites to receive a diagnosis of localized disease and more likely to receive a diagnosis of distant disease whereas stage distributions were approximately the same for males and females. Blacks were more likely than whites to receive a diagnosis of proximal colon cancer than distal colorectal cancer. The male-to-female rate ratios progressively increased from the proximal colon to the distal colorectum. The ratios of proximal-to-distal colorectal cancer gradually increased with advancing age. CONCLUSIONS: Differentials in stage of disease by subsites indicate a need for a targeted effort at early detection of cancer in the proximal colon. Risk factors and higher risk populations for colorectal cancers in each subsite need to be studied further to guide actions for improving the efficacy of screening.

Occupation and adult gliomas.

Lifetime job histories from a population-based, case-control study of gliomas diagnosed among adults in the San Francisco Bay area between August 1991 and April 1994 were evaluated to assess occupational risk factors. Occupational data for 476 cases and 462 controls were analyzed, with adjustment for age, gender, education, and race. Imprecise increased risks were observed for physicians and surgeons (odds ratio (OR) = 3.5, 95% confidence interval (CI): 0.7, 17.6), artists (OR = 1.9, 95% CI: 0.5, 6.5), foundry and smelter workers (OR = 2.6, 95% CI: 0.5, 13.1), petroleum and gas workers (OR = 4.9, 95% CI: 0.6, 42.2), and painters (OR = 1.6, 95% CI: 0.5, 4.9). Legal and social service workers, shippers, janitors, motor vehicle operators, and aircraft operators had increased odds ratios only with longer duration of employment. Physicians and surgeons, foundry and smelter workers, petroleum and gas workers, and painters showed increased risk for both astrocytic and nonastrocytic tumors. Artists and firemen had increased risk for astrocytic tumors only, while messengers, textile workers, aircraft operators, and vehicle manufacturing workers showed increased risk only for nonastrocytic tumors. Despite study limitations, including small numbers for many of the occupational groups, a high percentage of proxy respondents among cases, and lack of specific exposure information, associations were observed for several occupations previously reported to be at higher risk for brain tumors generally and gliomas specifically.

AIDS-related bronchogenic carcinoma: fact or fiction?

OBJECTIVE: Case reviews and retrospective analyses have raised the possibility of an increased frequency of primary lung carcinoma in HIV- and AIDS-infected patients. Conclusions have often been controversial and conflicting. We conducted a population-based epidemiologic study to assess the incidence of lung neoplasms in an HIV/AIDS cohort. MATERIALS AND METHODS: The Texas Department of Health generated descriptive data on lung neoplasms in HIV-AIDS patients whose conditions were diagnosed between 1990 and 1995. The cancer registry matched against all patients whose conditions were diagnosed during the same time interval. Relative risk was measured through standardized incidence ratios of lung neoplasms in the HIV-AIDS population as compared with that of the US population. RESULTS: The HIV-AIDS data file included 26,181 cases. A total of 76 lung cancer cases were identified, of which 36 (47.4%) were primary lung cancers. All major histologies were represented. The observed (36)/expected (5.6) ratio (standard incidence ratio) for primary lung cancer compared to the US population was 6.5 (4.5 to 8.9, 95% confidence interval). CONCLUSIONS: Our data indicate a 6.5-fold increased incidence of primary lung cancer in HIV- and AIDS-infected patients. We present the results of our study, a review of the work of other investigators, and address a potentially even greater public health problem in the HIV/AIDS population than previously realized.

Maternal exposure to N-nitrosatable drugs as a risk factor for childhood brain tumours.

BACKGROUND: Animal models suggest that compounds containing a nitrosyl group (N-nitroso compounds (NNO)) can act as potent transplacental carcinogens. Many common drug formulations have the potential to undergo nitrosation in vivo. The association between maternal use of nitrosatable drugs during pregnancy and development of brain tumours in the offspring was examined in a SEER-based case-control study. METHODS: Maternal exposure to nitrosatable drugs during pregnancy was compared among 361 childhood brain tumour cases and 1083 matched controls recruited through random-digit dialing. RESULTS: There was no increase in risk observed for childhood brain tumours overall (OR = 1.15; 95% CI: 0.69-1.94) or for astrocytomas individually (OR = 1.16; 95% CI: 0.50-2.69). A slight elevation in risk was noted for medulloblastomas (OR = 1.47; 95% CI: 0.28-7.62) and 'other' tumours (OR = 1.27; 95% CI: 0.56-2.86), however, both estimates were based on small numbers. CONCLUSIONS: Our findings suggest that no increased risk of childhood brain tumours was associated with maternal exposure to nitrosatable drugs. The study results should be viewed with caution given the imprecision of the point estimates as well as the lack of data on specific timing and dosage of exposure and degree of nitrosatability of drugs taken.